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Hello,<br>
<br>
I am still progressing with very high compression and I have corrected a
processing, so now very high compression (-l10 to -l13 quality
settings) has really better precision and so better quality.<br>
<br>
I have also released a first draft of a new -l14 very high compression quality setting.<br>
<br>
More at: <a href="http://nhwcodec.blogspot.com/" target="_blank">http://nhwcodec.blogspot.com/</a><br>
<br>
Just a remark, the entropy coding schemes start to be less efficient at
-l14 very high compression, and we can really improve them and save
bits.For example the coding of the wavelet DC coefficients, wavelet DC
image is far from optimal.I have 4 compression modes for 4 different
data nature for the wavelet DC image, but I just choose the overall
best coding mode for the whole wavelet DC image... this is not optimal,
I can really save bits if for example I split the wavelet DC image in
16x16 blocks, and give the one appropriate mode to each block, adapted
to its nature.<br>
<br>
Again using paq8px compressor, and simply compressing the .nhw compressed files, we see that we can save 2.5KB per .nhw file...<br>
<br>
Any feedback on the new -l14 quality setting and on the quality improvements is, as usual, very welcome!<br>
<br>
Many thanks again!<br>
Cheers,<br>
Raphael
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